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Homework Help: Express a function - Trigonometic Problem

  1. May 3, 2012 #1

    okh

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    Right Trapezium - Simple Problem Using Trigonometry

    1. The problem statement, all variables and given/known data
    http://img207.imageshack.us/img207/8510/imagejat.jpg [Broken]
    ABCD is a right trapezium. CB = 3 = CD. P is a point of CB. The angle CDP is called x.
    I have to express the function
    f(x) = DP + CP
    and I have to find the interval in which the function can be considered.
    2. Relevant equations



    3. The attempt at a solution
    I've found the function:
    http://img836.imageshack.us/img836/848/imageuox.jpg [Broken]

    But I can't understand how I can find the interval.
    Thank you very much for helping!

    PS: the solution on my book is 0<=x<=30º.
     
    Last edited by a moderator: May 6, 2017
  2. jcsd
  3. May 3, 2012 #2

    SammyS

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    Re: Right Trapezium - Simple Problem Using Trigonometry

    What are the possible values of DP + CP ?
     
    Last edited by a moderator: May 6, 2017
  4. May 3, 2012 #3

    okh

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    Uhm.. What do you mean? It depends on which x you choose. The function express that sum, indeed.
     
  5. May 3, 2012 #4
    There is a minimum value for DP + CP and a maximum value for DP + CP. What is the range of values and how does that relate to choices of x in your equation?
     
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